FOR JAVA PLEASE!

Farm class: o Add a method void exit(String filename)

• [+4] The method saves the farm data to a file named filename. Farm data includes at least availableFood and animals (i.e. the array with all animal instances)

• [+1] Once saved, display a message that data was saved successfully.

• [+4] If errors (exceptions) happen during the saving process, the method should print

  an error message. You should have at least two catch statements (one of them is

  FileNotFoundException).

• [+1] Make sure your code closes the output stream regardless of whether an error

  happens or not.

• [+2] Implement any required changes in your code (e.g. in other classes) so that this

  method works.

package P3;

public abstract class Animal implements Cloneable, Comparable{ /* Q: why it makes sense that Animal should be abstract? * A: Animal should be abstract to prevent creating animals of unknown types (i.e. that are not Cows, Llamas, or Chicken). * Animal just provides a base for its subclasses which inherit the implemented methods and are forced to implement the abstract methods. */ private String name; private double energy, mealAmount, x, y, speedX=1, speedY=1; private boolean alive; public Animal() { setEnergy(100); } public void speak(String msg){ if (isAlive()) System.out.println(getName() + " says: " + msg); } public double eat(){ if (isAlive()) { double amount = Math.round((100-getEnergy())*100)/100.0; if (amount >= mealAmount) { System.out.println(getName() + " ate " + mealAmount + " units"); setEnergy(getEnergy() + mealAmount); return mealAmount; } else if (amount > 0) { System.out.println(getName() + " ate " + amount + " units. Now it is full!"); setEnergy(100); return amount; } else { System.out.println(getName() + " didn't eat. It is full!"); return 0; } } else { System.out.println(getName() + " is dead!"); return 0; } } public void move() { if(isAlive()){ x += speedX; y += speedY; setEnergy(getEnergy() - 0.1); }else System.out.println(getName() + "can't move. It is dead!"); } public abstract void sound(); /* Q: why it makes sense for sound() to be be abstract? * Since we don't have unknown animals with unknown sounds, it doesn't make sense to implement 'sound()' in Animal * why not just delete it from Animal? * (a) we want to force all subclasses to include a sound method. * (b) having sound() defined in the superclass will allow calling it using a superclass reference (polymorphism) */

//compareTo, clone public Object clone() throws CloneNotSupportedException{ return super.clone(); } public int compareTo(Animal otherAnimal){ if(this.energy < otherAnimal.energy) return -1; else if(this.energy > otherAnimal.energy) return 1; else return 0; /* Another solution (50% of the mark only): return (int)(this.energy - otherAnimal.energy); //code above is ok but gets only 50% of the mark - since casting will lose precision (e.g. if difference is < 0.5, method will return 0 indicating the two energies are the same) */ } //setters, getters, toString public String getName() { return name; } public double getEnergy() { return energy; } public void setName(String name) { this.name = name; } public void setEnergy(double energy) { if(energy>0 && energy <=100) this.energy = energy; if(this.energy <= 17 ) System.out.println(getName() + " says: I'm STARVING"); else if(this.energy <= 50) System.out.println(getName() + " says: I'm hungry"); this.alive = (energy > 0); } public double getMealAmount() { return mealAmount; } public void setMealAmount(double mealAmount) { if(mealAmount>0 && mealAmount<100) this.mealAmount = mealAmount; } public double getX() { return x; } public void setX(double x) { this.x = x; } public double getY() { return y; } public void setY(double y) { this.y = y; } public double getSpeedX() { return speedX; } public void setSpeedX(double speedX) { this.speedX = speedX; } public double getSpeedY() { return speedY; } public void setSpeedY(double speedY) { this.speedY = speedY; } public boolean isAlive() { return alive; } public String toString(){ //return String.format("Alive:%b Name:%-10sEnergy:%-7.1fLocation:(%-2.1f,%-2.1f)", isAlive(), name, energy,x,y); return String.format("%-8s: %-5s at (%-2.1f,%-2.1f) Energy=%-7.1f", name, isAlive()?"alive":"dead",x,y,energy); } }